1. Field of the Invention
This invention relates to a solid-state image sensing device and in particular to a package structure of a solid-state image sensing device which is light in weight.
2. Description of the Prior Art
In a solid-state image sensing device of the prior art, a solid-state image sensing element 1 is packaged on a ceramic substrate 11 through an adhesive and is connected to external terminals through metal connecting wires 4 and lead frames 9, as shown in FIGS. 1A and 1B. One end of each lead frame 9 and is connected to the metal wire 4 on the substrate 11, and the remaining part of the lead frame 9 is drawn out and is connected to the external terminal. The image sensing device is provided with a dam frame 10, on top of the lead frames 9 on the substrate 11, which is adhered through an adhesive such as a low melting point glass or the like, and further is provided with a cover 3 which is adhered to top of the dam frame 10 through the low melting point glass as mentioned above.
In the above-mentioned prior solid-state image sensing device, there were some problems that the cover 3 must be in a shape of a flat plate since the cover 3 is made of a surface-processed glass, that the production cost is high since the dam frame 10 must be mounted on top of the lead frames 9 so that the solid-state image sensing element 1 and metal wires 4 are not crushed before the cover 3 is mounted, and that the element 1 must be separated from the dam frame 10 to a certain degree since a tool for mounting the metal wires 4 hits the dam frame 10, for example, in a step of connecting the element 1 to the substrate 11.
In addition, if an inorganic material, such as ceramics or the like, which has the coefficient of expansion close to that of glass, is not used as a material for the substrate 11, the cover 3 is cracked during a temperature cycle test since the cover 3 is made of glass. For this reason, there was a problem that the whole package weighs heavier.